Most tissue expanders and soft tissue-simulating implantable prostheses have been utilized to enhance or reconstruct the female breast. While success has been achieved across the spectrum of devices and procedures, the predictability of success has very often been a matter of intelligent guesswork by implanting surgeons. Despite the sometimes fortuitous selection of patients with low allergic response to polysiloxane implant fillers, the search for a broadly acceptable implant configuration has been protracted by differing implant shell and surface topographies, and by the range of quality of surgical outcomes. Silicone gel-filled implants, having the seductive ex vivo visual and tactile characteristics of clear transparency and gel consistency, have driven the “criteria” for such an implant rather than has the clinically more beneficial criterion of non-antigenicity.
Ultimately, it has become clear that silicone oils originating inside a gel-filled implant could manifest on the exterior surface of the shell, and being antigenic, could stimulate a self-protective response on the part of the patient. As a consequence, very dense tough scar tissue forms which serves to deform and severely harden what would otherwise be a soft breast. Such failures have stimulated a wider search for possible solutions including changes in surgical technique such as placing the implant, usually gel-filled silicone, into the sub-pectoral position. Sub-muscular placement of implants has increased the complication rate.
Complex multi-component implant constructions including textured shells, “protective” saline compartmentalization around silicone gel compartments, and baffling schemes and others have been tried and eventually rejected as being problematic for a variety of reasons. Likewise, triglyceride fillers and others have met similar fates.
Various other topologies, coverings and texturizing methods and structures have been contributed to the art. See for example my earlier U.S. Pat. No. 4,955,907 entitled “Implantable Prosthetic Device”, and U.S. Pat. No. 6,228,116 entitled “Tissue Expander”. Those patents are hereby incorporated by reference as if fully set forth herein.
FIG. 1 is a vertical cross-section of a prior art multi-compartment saline implant, specifically FIG. 21 from my U.S. Pat. No. 5,282,856. It illustrates a sessile normal saline-filled compartment adherent to the internal base of the implant surrounded and in contact with the contents of the surrounding volume, here a sponge. FIG. 2 is a vertical cross-section of a prior art saline implant, specifically FIG. 23 from my U.S. Pat. No. 5,282,856, whose entire volume is occupied by spheres of different diameters. My U.S. Pat. No. 5,282,856 is hereby incorporated by reference as if fully set forth herein, with the identified figures being specifically incorporated by reference as if fully set forth herein.
Yet, a safer natural alternative, the saline-filled implant has always been available. Unfortunately, resistance to its broad adoption has been based on esthetic consideration both ex vivo and as implanted. Its acceptance has been limited by its less than satisfactory “off-clear” appearance, the propensity to wrinkle due to a stiff high density shell and the fact that normal saline filler itself offers little resistance to deformation and is too quick to propagate visible waves on deformation. Such features have often led to embarrassment for the patient. Thus, there is an ongoing need for an enhanced performance saline implant which simulates the tactile features and performance of a silicone elastomer gel-filled implant but which lacks the antigenicity of filler silicone oils.